Sample surface inspection apparatus and method

Abstract

The present invention provides a surface inspection method and apparatus for inspecting a surface of a sample, in which a resistive film is coated on the surface, and a beam is irradiated to the surface having the resistive film coated thereon, to thereby conduct inspection of the surface of the sample. In the surface inspection method of the present invention, a resistive film having an arbitrarily determined thickness t 1 is first coated on a surface of a sample. Thereafter, a part of the resistive film having the arbitrarily determined thickness t 1 is dissolved in a solvent, to thereby reduce the thickness of the resistive film to a desired level. This enables precise control of a value of resistance of the resistive film and suppresses distortion of an image to be detected.

We claim: 
     
       1. A mechanism for inspecting a surface of a sample, comprising:
 an electro-optical inspection apparatus comprising: 
 an electromagnetic wave source for irradiating the sample surface with electromagnetic waves; 
 an electron source consisting of an electron gun for emitting an electron beam in a direction which is not perpendicular to the sample surface; and 
 an EXB deflector for deflecting the electron beam emitted from the electron source to irradiate the sample surface therewith in a direction which is perpendicular to the sample surface, and passing photoelectrons emitted from the sample surface when it is irradiated with the electromagnetic waves, and electrons from the sample surface when it is irradiated with the electron beam; 
 a detector for detecting the photoelectrons and electrons, respectively which are passed through the EXB deflector to output electric signals associated with the detected photoelectrons and electrons, respectively; and 
 a processing unit for processing the signals output from the detector and forming an image associated with the sample surface. 
 
     
     
       2. A mechanism according to  claim 1 , wherein the electro-optical inspection apparatus further comprises an objective lens system comprising at least two lenses located between the sample surface and the EXB deflector, and an enlarging lens system comprising at least two lenses and located between the EXB deflector and the detector. 
     
     
       3. A mechanism according to  claim 1 , wherein the electro-optical inspection apparatus further comprises an objective lens system comprising at least two lenses located between the sample surface and the FXB deflector, and two enlarging lens systems each comprising at least two lenses and located between the EXB deflector and the detector. 
     
     
       4. A mechanism according to  claim 1 , wherein the electro-optical inspection apparatus is an image projection type inspection apparatus. 
     
     
       5. A mechanism according to  claim 1 , wherein a diameter of the electromagnetic waves irradiated on the sample surface is in a range of about 10 μm-10 mm. 
     
     
       6. A mechanism according to  claim 1 , a diameter of a field of view of the electron beam is about 10 μm-10 mm. 
     
     
       7. A mechanism according to  claim 1 , further comprising a control electrode to supply a voltage to control a field strength on the sample surface, to thereby reduce aberration of the photoelectrons or electrons emitted from the sample surface. 
     
     
       8. A mechanism according to  claim 1 , wherein the sample is at least one of a semiconductor wafer with a resistive film thereon, a photo-mask and reticle-mask. 
     
     
       9. A mechanism according to  claim 1 , wherein the electromagnetic wave source irradiates the sample surface with the electromagnetic waves in a direction which is not perpendicular to the sample surface. 
     
     
       10. A method of inspecting a surface of a sample, comprising:
 actuating one or both of the electromagnetic wave source and the electron source in accordance with a kind of the sample; 
 irradiating the sample surface with one or both of the electromagnetic waves and the electron beam which are/is emitted from the actuated source; 
 detecting either of photoelectrons and electrons emitted from the sample surface by the detector to output the signal; and 
 processing the signal by the processing unit to obtain an image of the sample surface. 
 
     
     
       11. A method according to  claim 10 , wherein the sample surface is coated with a resistive film.